The invention relates to a digital time division multiplex (TDM) telecommunication network wherein the subscriber terminals are selectively connected in a defined sequence to a common TDM network path or highway and then through a central office. The TDM highway begins at the central office, and it ultimately ends there. The telecommunication data in each pulse frame for subscriber terminals involved in calls are transmitted in the sequence of their connection to the TDM highway and are received by the first subscriber terminal that has not yet been supplied with information whereupon the latter immediately thereafter transmits in an outgoing direction to the central office the information to be sent by it past subsequent subscriber terminals.
Unbranched systems of the above type are known, for example, in West German patent application No. P 24 38 199.5-31 the TDM highway is a single unbranched path. A copy of the West German patent application No. P 24 38 199.5-31 can be found in the application file. A translation of this West German patent application also can be found in the application file. This translation corresponds to U.S. Pat. No. 4,051,328 in which foreign priority was claimed based on West German patent application No. P 24 38 199.5-31. This U.S. Pat. No. 4,051,328 was issued on Sept. 27, 1977 to the same inventor and assigned to the same assignee as the present invention.
Even in the region of a local central office there may be a need for a branched system, namely, if there are remote groups of terminals.
If, as assumed hereinabove, the TDM highway begins from the central office and terminates therein, i.e., if only one looped circuit is provided, the interruption of such a loop at any point means the breakdown of the entire network of terminals.
Therefore, it is an object of the invention to provide for a telecommunication network of the type mentioned hereinabove having a branching structure for accommodating remote groups of subscriber terminals whereby, in addition, complete breakdowns are avoided.